Distributed control and power management strategy for an autonomous hybrid microgrid with multiple sub-microgrids

Abstract

This paper proposes a novel approach of distributed coordination control for multiple sub-microgrids (SMGs) within a hybrid AC/DC microgrid. The conventional control approach for managing power flow among AC and DC SMGs is based on the proportional power sharing principle. This is mainly implemented by equalising the normalized voltage at the DC side and the frequency at the AC side for any interfaced SMGs. The proposed method suggests a distributed control system that ensures a total controllability for the interlinking converters. It overcomes the total dependency on a specific variable for power exchange. The proposed method not only enables control of the power flow between SMGs but also ensures the continuity of power transfer if any single SMG fails. Three case studies are presented to demonstrate the validity and capability of the proposed approach using the MATLAB/Simulink software. From the obtained results, it is found that the proposed control system provides a high level of flexibility in managing the power flow among SMGs.